543 research outputs found

    Preoperative portal vein embolization with a combination of trisacryl microspheres, gelfoam and coils

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    AbstractPurposeTo evaluate the safety and efficiency of preoperative portal vein embolization (PVE) with a combination of trisacryl microspheres, gelfoam and coils for inducing lobar hypertrophy in hepatobiliary malignancy patients.Materials and methodsPVE was performed by a percutaneous left approach in 63 patients with hepatic malignancy (hepatocarcinoma=38, colorectal metastasis=14, cholangiocarcinoma=11). The indication of PVE and surgery was evaluated by hepatic tumor board take into consideration to the tumor extension and the hepatic volume on initial and post-embolization CT-scans. The total functional liver volume (TELV) and future liver remnant (FLR) volume were measured before and 24±5days after PVE to assess FLR, TELV and FLR/TELV ratios. Efficiency evaluation was based on FLR increase, the ability to perform the hepatectomy and the hepatic function after surgery. Safety evaluation was determined by clinical and biological follow-up after embolization and surgery.ResultsPVE was successful in all the patients. The mean FLR volume increases by 57±56% after embolization (449±180cm3 to 663±254cm3) (P<0.0001). The FLR/TELV ratio increases by 11% after PVE (25±8% to 36±12%). Three minors’ complications were registered without impact on surgery, and four patients developed portal hypertension. Forty-nine patients underwent hepatectomy; none of them developed liver failure. Surgery was not performed in 14 patients due to tumor progression (n=9), inadequate hypertrophy of FLR (n=1) and portal hypertension (n=4).ConclusionPreoperative PVE with a combination of trisacryl microspheres, gelfoam and coils is a safe and effective method for inducing contralateral hypertrophy before right hepatectomy in patients with advanced hepatobiliary malignancy

    Normalisation genes for expression analyses in the brown alga model Ectocarpus siliculosus

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    <p>Abstract</p> <p>Background</p> <p>Brown algae are plant multi-cellular organisms occupying most of the world coasts and are essential actors in the constitution of ecological niches at the shoreline. <it>Ectocarpus siliculosus </it>is an emerging model for brown algal research. Its genome has been sequenced, and several tools are being developed to perform analyses at different levels of cell organization, including transcriptomic expression analyses. Several topics, including physiological responses to osmotic stress and to exposure to contaminants and solvents are being studied in order to better understand the adaptive capacity of brown algae to pollution and environmental changes. A series of genes that can be used to normalise expression analyses is required for these studies.</p> <p>Results</p> <p>We monitored the expression of 13 genes under 21 different culture conditions. These included genes encoding proteins and factors involved in protein translation (ribosomal protein 26S, EF1alpha, IF2A, IF4E) and protein degradation (ubiquitin, ubiquitin conjugating enzyme) or folding (cyclophilin), and proteins involved in both the structure of the cytoskeleton (tubulin alpha, actin, actin-related proteins) and its trafficking function (dynein), as well as a protein implicated in carbon metabolism (glucose 6-phosphate dehydrogenase). The stability of their expression level was assessed using the Ct range, and by applying both the geNorm and the Normfinder principles of calculation.</p> <p>Conclusion</p> <p>Comparisons of the data obtained with the three methods of calculation indicated that EF1alpha (EF1a) was the best reference gene for normalisation. The normalisation factor should be calculated with at least two genes, alpha tubulin, ubiquitin-conjugating enzyme or actin-related proteins being good partners of EF1a. Our results exclude actin as a good normalisation gene, and, in this, are in agreement with previous studies in other organisms.</p

    Combined Weekly Coordinate Solutions from SLR and DORIS

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    In International Terrestrial Reference Frame (ITRF) 2005 and ITRF2008, the approach for the construction of solutions by the IERS has been for individual analysis centers of each technique to process geodetic tracking data, and for each technique to develop a solution (or contribution) that is integrated into the final ITRF solution by careful combination of the technique solutions. The connections between the geodetic networks are realized by the application of local ties. In an alternate approach, we may assure processing homogeneity by creating normal equations for different techniques with the same orbit determination software, using identically derived algorithms. Another derivative of this approach is to realize the ties between the techniques using satellites tracked with multiple techniques; in effect tieing the networks together using satellite dynamics. In this solution, we develop a time series and a set of cumulative solutions from Satellite Laser Ranging (SLR) & Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS) based on homogeneous processing with the NASA GEODYN precise orbit determination suite of programs, where we jointly combine weekly the SLR data to Lageos1, Lageos2, Starlette, and Stella with the DORIS data from SPOT2-SPOT5, as well as satellites that utilize both techniques (TOPEX/Poseidon, Envisat, Jason-2). We discuss the modeling that is applied including upgrades implemented since the submission of the GSC ITRF2008 contributions for IDS. Firstly, we compare the SLR-only solutions comprising four geodetic satellites with the standard approach of utilizing only Lageos1 & Lageos2. Secondly, we evaluate the impact on the DORIS coordinates of the joint analysis with the SLR data

    Development and physiology of the brown alga Ectocarpus siliculosus: two centuries of research

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    International audienceBrown algae share several important features with land plants, such as their photoautotrophic nature and their cellulose‐containing wall, but the two groups are distantly related from an evolutionary point of view. The heterokont phylum, to which the brown algae belong, is a eukaryotic crown group that is phylogenetically distinct not only from the green lineage, but also from the red algae and the opisthokont phylum (fungi and animals). As a result of this independent evolutionary history, the brown algae exhibit many novel features and, moreover, have evolved complex multicellular development independently of the other major groups already mentioned. In 2004, a consortium of laboratories, including the Station Biologique in Roscoff and Genoscope, initiated a project to sequence the genome of Ectocarpus siliculosus, a small filamentous brown alga that is found in temperate, coastal environments throughout the globe. The E. siliculosus genome, which is currently being annotated, is expected to be the first completely characterized genome of a multicellular alga. In this review we look back over two centuries of work on this brown alga and highlight the advances that have led to the choice of E. siliculosus as a genomic and genetic model organism for the brown algae

    Determination of the high-pressure crystal structure of BaWO4 and PbWO4

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    We report the results of both angle-dispersive x-ray diffraction and x-ray absorption near-edge structure studies in BaWO4 and PbWO4 at pressures of up to 56 GPa and 24 GPa, respectively. BaWO4 is found to undergo a pressure-driven phase transition at 7.1 GPa from the tetragonal scheelite structure (which is stable under normal conditions) to the monoclinic fergusonite structure whereas the same transition takes place in PbWO4 at 9 GPa. We observe a second transition to another monoclinic structure which we identify as that of the isostructural phases BaWO4-II and PbWO4-III (space group P21/n). We have also performed ab initio total energy calculations which support the stability of this structure at high pressures in both compounds. The theoretical calculations further find that upon increase of pressure the scheelite phases become locally unstable and transform displacively into the fergusonite structure. The fergusonite structure is however metastable and can only occur if the transition to the P21/n phases were kinetically inhibited. Our experiments in BaWO4 indicate that it becomes amorphous beyond 47 GPa.Comment: 46 pages, 11 figures, 3 table

    Binding loci of RelA-containing nuclear factor-kappaB dimers in promoter regions of PHM1-31 myometrial smooth muscle cells.

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    Human parturition is associated with many pro-inflammatory mediators which are regulated by the nuclear factor-kappaB (NF-ÎșB) family of transcription factors. In the present study, we employed a ChIP-on-chip approach to define genomic loci within chromatin of PHM1-31 myometrial cells that were occupied by RelA-containing NF-ÎșB dimers in response to a TNF stimulation of 1 h. In TNF-stimulated PHM1-31 cells, anti-RelA serum enriched 13 300 chromatin regions; importantly, 11 110 regions were also enriched by anti-RelA antibodies in the absence of TNF. DNA sequences in these regions, from both unstimulated or TNF-stimulated PHM1-31 cultures, were associated with genic regions including IÎșBα, COX-2, IL6RN, Jun and KCNMB3. TNF-induced binding events at a consensus ÎșB site numbered 1667; these were represented by 112 different instances of the consensus ÎșB motif. Of the 1667 consensus ÎșB motif occurrences, 770 (46.2%) were identified within intronic regions. In unstimulated PHM1-31 cells, anti-RelA-serum-enriched regions were associated with sequences corresponding to open reading frames of ion channel subunit genes including CACNB3 and KCNB1. Moreover, in unstimulated cells, the consensus ÎșB site was identified 2116 times, being defined by 103 different sequence instances of this motif. Of these 2116 consensus ÎșB motifs, 1089 (51.5%) were identified within intronic regions. Parallel expression array analyses in PHM1-31 cultures demonstrated that TNF stimulated a >2-fold induction in 51 genes and a fold repression of >1.5 in 18 others. We identified 14 anti-RelA-serum-enriched genomic regions that correlated with 17 TNF-inducible genes, such as COX2, Egr-1, Jun, IÎșBα and IL6, as well as five regions associated with TNF-mediated gene repression, including Col1A2

    Quantification of portal–bridging fibrosis area more accurately reflects fibrosis stage and liver stiffness than whole fibrosis or perisinusoidal fibrosis areas in chronic hepatitis C

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    International audienceMorphometry provides an objective evaluation of fibrosis in liver diseases. We developed an image analysis algorithm using automated thresholding and segmentation to separately quantify the areas and the fractal dimensions of portal–bridging fibrosis and perisinusoidal fibrosis in chronic hepatitis C liver biopsies. We studied 427 digitized liver biopsies and compared the automated measures of the different fibrosis compartments with (1) the Metavir F (fibrosis) and A (activity) histological scores, (2) the digitally assessed area of steatosis, and (3) the liver stiffness measured by elastography (Fibroscan). The perisinusoidal fibrosis area was higher than that of portal fibrosis in stages ≀F2; it reached its highest value in F2 stage and stabilized thereafter. The F3 stage was characterized by equal proportions of portal–bridging and perisinusoidal fibrosis, whereas portal–bridging area was predominant in cirrhosis. Measurement of portal–bridging fibrosis showed highly significantly different values between contiguous F stages; the ratio of portal–bridging fibrosis/perisinusoidal fibrosis displayed less overlap between Metavir stages than did the whole fibrosis area values. Fractal dimension showed that portal–bridging fibrosis tended to display a homogeneous surface-like spatial organization, whereas perisinusoidal fibrosis appeared more heterogeneous according to stage and curvilinear. The portal–bridging fibrosis area was low in cases with low Metavir activity and little steatosis, and became predominant with increasing activity and steatosis. Using stepwise multiple linear regression analysis, the liver stiffness was independently correlated to the portal–bridging fibrosis area (first step, P<0.001), the steatosis area (second step, P<0.001), and the Metavir A grade (third step, P=0.001), but not to the perisinusoidal fibrosis area. Automated quantification in a large cohort of chronic hepatitis C showed that perisinusoidal fibrosis progressively grew in early fibrosis stages but did not increase in septal or cirrhotic stages and that the portal–bridging fibrosis area appeared as a more accurate tool to assess fibrosis progression than the whole fibrosis area

    High pressure phases in highly piezoelectric Pb(Zr0.52Ti0.48)O3

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    Two novel room-temperature phase transitions are observed, via synchrotron x-ray diffraction and Raman spectroscopy, in the Pb(Zr0.52Ti0.48)O3 alloy under hydrostatic pressures up to 16 GPa. A monoclinic (M)-to-rhombohedral (R1) phase transition takes place around 2-3 GPa, while this R1 phase transforms into another rhombohedral phase, R2, at about 6-7 GPa. First-principles calculations assign the R3m and R3c symmetry to R1 and R2, respectively, and reveal that R2 acts as a pressure-induced structural bridge between the polar R3m and a predicted antiferrodistortive R-3c phase.Comment: REVTeX, 4 pages with 3 figures embedded. Figs 1 and 3 in colo
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